全文获取类型
收费全文 | 1094篇 |
免费 | 22篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 92篇 |
废物处理 | 51篇 |
环保管理 | 163篇 |
综合类 | 186篇 |
基础理论 | 241篇 |
环境理论 | 1篇 |
污染及防治 | 234篇 |
评价与监测 | 78篇 |
社会与环境 | 71篇 |
灾害及防治 | 8篇 |
出版年
2023年 | 9篇 |
2022年 | 16篇 |
2021年 | 27篇 |
2020年 | 20篇 |
2019年 | 12篇 |
2018年 | 31篇 |
2017年 | 51篇 |
2016年 | 51篇 |
2015年 | 42篇 |
2014年 | 48篇 |
2013年 | 95篇 |
2012年 | 47篇 |
2011年 | 81篇 |
2010年 | 46篇 |
2009年 | 49篇 |
2008年 | 63篇 |
2007年 | 69篇 |
2006年 | 46篇 |
2005年 | 42篇 |
2004年 | 39篇 |
2003年 | 41篇 |
2002年 | 32篇 |
2001年 | 19篇 |
2000年 | 14篇 |
1999年 | 16篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 8篇 |
1995年 | 13篇 |
1994年 | 15篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 9篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有1125条查询结果,搜索用时 187 毫秒
691.
Regional Environmental Change - Global cities are taking a leadership role in climate change adaptation. Increasing numbers of cities are creating climate adaptation plans and strategies, and a... 相似文献
692.
693.
Michal Petr L. G. J. Boerboom Duncan Ray Anne van der Veen 《Regional Environmental Change》2016,16(4):1161-1170
Information helps decision makers to address and to decide about environmental problems. In the context of climate change adaptation, often knowledge is missing on how the available information from impact models affects the decision-making process. The main aim of this study was to explore the extent of ambiguity and how new climate change information influenced decision of forest planners. We investigated changes in decisions of planners about forestry actions representing species choice and forest tourism and expiry dates of these actions leading to environmental constraints in the provision of ecosystem services. Forest planners evaluated expiry dates using four forest ecosystem services: forest production, stand yield class, sequestered carbon, and potential tourism. Data were collected during workshops with eleven forest planners from three forest districts in Scotland. Presented climate change information modified the understanding and frames of planners about forestry actions assessed with accompanying expiry dates. Changes in the frames of planners often result in both earlier and later expiry dates. Ambiguity of planners was found to be dependent on diversity in frames and difficulty in evaluating multiple ecosystem services. These findings imply that due to ambiguity forest planners might find it hard to choose climate change adaptation measures and researchers can struggle to convince planners with new research findings. 相似文献
694.
695.
Sandra Tostar Erik Stenvall Antal Boldizar Mark R. St. J. Foreman 《Waste management (New York, N.Y.)》2013,33(6):1478-1482
There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5 M) dissolved in either dimethyl sulfoxide or water (at ca. 23 °C and heated to ca. 105 °C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed. 相似文献
696.
Anne Algers Berner Lindström Edmond A. Pajor 《Journal of Agricultural and Environmental Ethics》2011,24(4):367-379
Farm animal welfare is a knowledge domain that can be regarded as a model for new ways of organizing learning and making higher
education more responsive to the needs of society. Global concern for animal welfare has resulted in a great demand for knowledge.
As a complement to traditional education in farm animal welfare, higher education can be more demand driven and look at a
broad range of methods to make knowledge available. The result of an inventory on “farm animal welfare,” “e-learning,” “learning
resources,” and “open educational resources” in three different search engines is presented. A huge amount of information
on animal welfare is available on the Internet but many of the providers lock in the knowledge in a traditional course context.
Only a few universities develop and disseminate open learning resources within the subject. Higher education institutions
are encouraged to develop open educational resources in animal welfare for the benefit of teachers, students, society, and,
indirectly, animal welfare. 相似文献
697.
Thimonier A Kull P Keller W Moser B Wohlgemuth T 《Environmental monitoring and assessment》2011,174(1-4):47-63
At Swiss long-term forest ecosystem research sites, ground vegetation was assessed during the period 1994-2003/2008 following two approaches: (1) visual assessment of the cover of species occurring in sixteen 1 m(2) quadrats, distributed over a 43 × 43 m area, and (2) phytosociological relevés in concentric circular plots of 30, 200, and 500 m(2). We first compared the two approaches with respect to diversity assessment. The number of species recorded in the 16 quadrats was in general higher than in the 30 m(2) plot and it represented 42% to 108% of the number of species recorded in the 500 m(2) plot. In a second step, we tested whether any temporal trends were apparent. In a few cases, a decrease or increase in Landolt's mean indicator values for light, nitrogen availability, soil pH, soil moisture, or temperature was found to be significant. However, these changes were usually restricted to one approach or one area. The only clear trend was detected in an unmanaged former coppice beech stand, for which all survey approaches indicated canopy closure. At another site, vegetation reacted to the local opening of the canopy following windthrow. In a third step, we compared the leaf area index (LAI), measured with an LAI-2000 instrument (Licor, Inc.) over each quadrat, with the indicator value of the vegetation for light (L). Within a site, there was no clear relationship between LAI and L values per quadrat. In contrast, across all sites, the relationship between LAI and L, averaged per site for all available years, was highly significant. 相似文献
698.
Objective
To estimate the effects of red light camera enforcement on per capita fatal crash rates at intersections with signal lights.Methods
From the 99 large U.S. cities with more than 200,000 residents in 2008, 14 cities were identified with red light camera enforcement programs for all of 2004-2008 but not at any time during 1992-1996, and 48 cities were identified without camera programs during either period. Analyses compared the citywide per capita rate of fatal red light running crashes and the citywide per capita rate of all fatal crashes at signalized intersections during the two study periods, and rate changes then were compared for cities with and without cameras programs. Poisson regression was used to model crash rates as a function of red light camera enforcement, land area, and population density.Results
The average annual rate of fatal red light running crashes declined for both study groups, but the decline was larger for cities with red light camera enforcement programs than for cities without camera programs (35% vs. 14%). The average annual rate of all fatal crashes at signalized intersections decreased by 14% for cities with camera programs and increased slightly (2%) for cities without cameras. After controlling for population density and land area, the rate of fatal red light running crashes during 2004-2008 for cities with camera programs was an estimated 24% lower than what would have been expected without cameras. The rate of all fatal crashes at signalized intersections during 2004-2008 for cities with camera programs was an estimated 17% lower than what would have been expected without cameras.Conclusions
Red light camera enforcement programs were associated with a statistically significant reduction in the citywide rate of fatal red light running crashes and a smaller but still significant reduction in the rate of all fatal crashes at signalized intersections.Impact on Industry
The study adds to the large body of evidence that red light camera enforcement can prevent the most serious crashes. Communities seeking to reduce crashes at intersections should consider this evidence. 相似文献699.
Ellen Hollands Steffensen Anne Skakkebæk Kasper Gadsbøll Olav Bjørn Petersen Thomas Westover Heather Strange The NIPT-SCA-map Study Group Ida Vogel 《黑龙江环境通报》2023,43(2):144-155
Objective
To examine the extent to which sex chromosomes are included in current noninvasive prenatal testing (NIPT) and the reporting practices with respect to fetal chromosomal sex and sex chromosome aberrations (SCAs), in addition to an update on the general implementation of NIPT.Method
A questionnaire addressing the research objectives was distributed by email to fetal medicine and clinical genetics experts in Asia, Australia, Europe and the USA.Results
Guidelines on NIPT are available in the majority of the included countries. Not all existing guidelines address reporting of fetal chromosomal sex and SCAs. In most settings, NIPT frequently includes sex chromosomes (five Australian states, China, Hong Kong, Israel, Singapore, Thailand, USA and 23 of 31 European countries). This occurs most often by default or when parents wish to know fetal sex. In most settings, a potential SCA is reported by stating the risk hereof as “low” or “high” and/or by naming the SCA. Less than 50% of all pregnant women receive NIPT according to respondents from three Australian states, China, Israel, Singapore, Thailand and 24 of 31 European countries. However, this percentage, the genomic coverage of NIPT and its application as primary or secondary screening vary by setting.Conclusion
In most of the studied countries/states, NIPT commonly includes sex chromosomes. The reporting practices concerning fetal chromosomal sex and SCAs are diverse and most commonly not addressed by guidelines. In general, NIPT is variably implemented across countries/states. 相似文献700.
Paiva Robert Veroneze Isabelly Bertochi Wrona Magdalena Nerín Cristina Cruz Sandra Andrea 《Journal of Polymers and the Environment》2022,30(2):494-503
Journal of Polymers and the Environment - Recycling of polymers is one of the alternatives to reduce the impact of polymers presence on the environmental. However, the contaminants, defined as... 相似文献